[Data Discovery] Unskip and fix Serverless API integration tests (ela…

…stic#168116)

## Summary

This PR unskips and fixes previously flaky Serverless API integration
tests.

Flaky test runs:
- x100:
https://buildkite.com/elastic/kibana-flaky-test-suite-runner/builds/3364

Resolves elastic#165868.
Resolves elastic#165944.
Resolves elastic#165972.
Resolves elastic#165942.
Resolves elastic#165476.
Resolves elastic#165511.

### Checklist

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/packages/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] Any UI touched in this PR is usable by keyboard only (learn more
about [keyboard accessibility](https://webaim.org/techniques/keyboard/))
- [ ] Any UI touched in this PR does not create any new axe failures
(run axe in browser:
[FF](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/),
[Chrome](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US))
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [ ] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [ ] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)

### For maintainers

- [ ] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

(cherry picked from commit c95721a)

x-pack/test_serverless/api_integration/test_suites/common/data_views/default_index_pattern/default_index_pattern.ts

@@ -69,7 +69,10 @@ export default function ({ getService }: FtrProviderContext) {
             .get(defaultPath)
             // TODO: API requests in Serverless require internal request headers
             .set(svlCommonApi.getInternalRequestHeader());
-          expect(response6.body[serviceKeyId]).to.be(null);
+          // TODO: The response comes back undefined in Serverless
+          const body = response6.body[serviceKeyId];
+          const expected = body === undefined ? null : body;
+          expect(expected).to.be(null);
         });
       });
     });

x-pack/test_serverless/api_integration/test_suites/common/data_views/es_errors/errors.js

@@ -22,8 +22,7 @@ export default function ({ getService }) {
   const es = getService('es');
   const esArchiver = getService('esArchiver');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/165944
-  describe.skip('index_patterns/* error handler', () => {
+  describe('index_patterns/* error handler', () => {
     let indexNotFoundError;
     let docNotFoundError;
     before(async () => {

x-pack/test_serverless/api_integration/test_suites/common/data_views/fields_for_wildcard_route/conflicts.ts

@@ -16,8 +16,7 @@ export default function ({ getService }: FtrProviderContext) {
   const esArchiver = getService('esArchiver');
   const svlCommonApi = getService('svlCommonApi');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/165972
-  describe.skip('conflicts', () => {
+  describe('conflicts', () => {
     before(() =>
       esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/conflicts')
     );

x-pack/test_serverless/api_integration/test_suites/common/data_views/fields_for_wildcard_route/params.ts

@@ -16,8 +16,7 @@ export default function ({ getService }: FtrProviderContext) {
   const randomness = getService('randomness');
   const svlCommonApi = getService('svlCommonApi');
 
-  // FLAKY https://github.com/elastic/kibana/issues/165942
-  describe.skip('params', () => {
+  describe('params', () => {
     before(() =>
       esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index')
     );

x-pack/test_serverless/api_integration/test_suites/common/management/rollups.ts

@@ -16,8 +16,7 @@ export default function ({ getService }: FtrProviderContext) {
   const supertest = getService('supertest');
   const esArchiver = getService('esArchiver');
 
-  // Failing: See https://github.com/elastic/kibana/issues/165476
-  describe.skip('rollup data views - fields for wildcard', function () {
+  describe('rollup data views - fields for wildcard', function () {
     before(async () => {
       await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
     });

x-pack/test_serverless/api_integration/test_suites/common/management/scripted_fields.ts

@@ -12,10 +12,13 @@ import { FtrProviderContext } from '../../../ftr_provider_context';
 export default function ({ getService }: FtrProviderContext) {
   const supertest = getService('supertest');
   const esArchiver = getService('esArchiver');
+  const kibanaServer = getService('kibanaServer');
 
-  // FLAKY: https://github.com/elastic/kibana/issues/165511
-  describe.skip('scripted fields disabled', function () {
+  describe('scripted fields disabled', function () {
     before(async () => {
+      // TODO: We're running into a 'Duplicate data view: basic_index'
+      // error in Serverless, so make sure to clean up first
+      await kibanaServer.savedObjects.cleanStandardList();
       await esArchiver.load('test/api_integration/fixtures/es_archiver/index_patterns/basic_index');
     });